Circuit Playground Bluefruit - ALPHA - Bluetooth Low Energy

Jargon buster

Plain-language definitions for the technical terms used above.

CircuitPython

A beginner-friendly version of Python designed to run directly on microcontroller boards. If a product supports CircuitPython, you can often program it by copying code files onto the board rather than setting up a more complex toolchain.

HID

Human Interface Device is a USB device class used for keyboards, mice, gamepads and similar controls. If a board supports HID over USB, it can act like an input device to a computer without needing a custom driver.

LED

A light-emitting diode (LED) is a small electronic component that emits light when current flows through it in the correct direction. Because it only conducts one way, its polarity matters, and a through-hole LED must be soldered the correct way around to light up.

LiPo

A LiPo (lithium polymer) battery is a rechargeable lithium battery widely used in portable projects because it is light and compact. LiPo cells need correct charging circuitry and careful handling to stay safe, so equipment that supports LiPo generally includes charging or protection hardware suited to that battery type.

LIS3DH

A specific low-power 3-axis accelerometer chip made by STMicroelectronics. Knowing the chip part number helps you find the correct datasheet, libraries, wiring details, and limits such as its safe voltage range.

MEMS microphone

A tiny microphone made using micro-electromechanical systems, the same style of miniature manufacturing used in many phone sensors. It lets the board detect sound without needing an external microphone, which is useful for noise-reactive projects and simple audio input.

microcontroller

A microcontroller is a small computer on a single chip that runs a stored program and controls connected inputs and outputs such as buttons, sensors, displays and communication interfaces. In a device built around one, it is the part that executes the code and coordinates the device's behaviour.

MIDI

MIDI is a standard way for electronic instruments, controllers, and software to send musical control messages such as notes, velocity, and timing. If a board supports MIDI, it can be triggered from keyboards, drum pads, sequencers, or other music gear rather than only from buttons or code.

nRF52840

The nRF52840 is a Nordic Semiconductor system-on-chip built around a 32-bit Arm Cortex-M4 processor, with built-in Bluetooth Low Energy and native USB. It is widely used in maker and wearable boards, where it offers BLE and USB support along with broad library coverage in common maker toolchains.

phototransistor

A light-sensitive transistor that changes its electrical output when light hits it. Compared with a modulated IR receiver, a simple phototransistor can be more affected by ambient light, so it may need extra filtering or careful setup.

PWM

Pulse Width Modulation is a way for a digital pin to simulate variable output power by switching on and off very quickly. It matters for controlling things like LED brightness, motor speed, or servo-style signals from a microcontroller pin.

RGB

Short for red, green and blue, the three primary colours of light that are mixed in varying amounts to make a wide range of colours. In electronics RGB can refer to an LED or pixel that blends these three colours, or to a colour signal or interface that carries separate red, green and blue channels.

SPI

A fast serial communication bus often used for displays, memory cards, and sensors. It matters because SPI devices need specific pins for clock and data, plus a separate chip-select line for each device.

UART

UART is a simple asynchronous serial interface that sends data over separate transmit and receive wires, usually labelled TX and RX, with both ends set to the same baud rate. It is a common way for microcontrollers and other serial devices to exchange data.